摘要：AbstractÇataldağ, a mountain located in the northeast of Balıkesir, is a granitic mass the summit of which has an elevation of 1327 meters (Çobandede). As it lies in east-west direction in terms of its location, there is a striking vegetation contrast between the north and south slopes. The wide distribution of characteristically hygrophilous elements such as Uludağ fir (Abies bornmülleriana) and beech (Fagus orientalis) on the north slopes of the mountain makes it very interesting. The purpose of this study is to reveal the reason behind this interesting situation and to describe the features of these two slopes by comparing them. The vegetation was examined on site, notes were taken, and samples were collected in the preparation phase of the study. Later, these findings were classified. Based on the observations and materials, a vegetation map with a scale of 1/25.000 was prepared by using forest management plans and topographic maps. Data provided by Mustafakemalpaşa and Kepsut meteorological stations, which respectively represent the north and south slopes, was used in order to find out about the relationship between the vegetation and the climate. Besides, 1/25.000 scaled geological and soil maps were drawn with the purpose of demonstrating the edaphic conditions of plant communities. In order to indicate the orographic influence, cross section views of the vegetation along the north and south slopes were generated. Çataldağ lies in east-west direction, and is about 50km away from the Marmara Sea as the crow flies. Thus, the north slopes are exposed to sea effects. The aspect, geographical position, and the elevation of the mountain led to the formation of a hygrophilous plant community. The study not only reveals that the aspect has a great influence on the vegetation of the north and south slopes of mountains, but also demonstrates that this area is a border between the phytogeographical regions of the Black Sea and the Mediterranean. In addition, the area is important in that it is the farthest western edge of the land where Uludağ fir (Abies bornmülleriana) grows. Beech communities, a dominant plant species on the north slopes, are found as islets and belts in regions situated in further west and south. This proves that Çataldağ is located in the Black Sea phytogeographical region.
